Volume 22 (2014) Issue 3 Pages 495-507
This paper provides a new device specification method, for file sharing among multiple partner devices on that spot (e.g., a meeting picture of a social gathering) and so forth. This is because the past representative solution of inputting or selecting the partner device address (e.g., e-mail address) sometimes irritates users and causes an operation error. The problem to be solved is the development of the method that satisfies the four requirements for the above use case: no need of awareness of the device address by users, simultaneous specification of multiple partner devices, differentiation of a device of a stranger, and no need for pre-planned infrastructure. To solve the problem, our method uses an operation of holding the user device in a hand and describing a circle in the air to surround the partner devices. During this operation, the devices exchange acoustic waves and generate the Doppler Effect. By analysis based on the Doppler Effect, the user can specify only the multiple devices that have been circled. Acoustic waves contribute to the relatively accurate detection of the Doppler Effect, due to their slower propagation velocity than that of electronic waves, e.g., Bluetooth and Wi-Fi. We explain the proposed method in detail, and measure its performance via an implemented application. The experimental results show that it enables the simultaneous specification of multiple devices located in the range within 10 degrees from the direction of the user operation, while distinguishing a device of a stranger located in the range larger than 45 degrees. In the above use case, after putting partner devices on a table, the proposed method of this performance satisfies the four requirements, even if a device of a stranger is located at the next table. Thus, this paper concludes that the proposed method is practical for the above use case.